Stormwater Management Program
Our health, livelihoods, and recreation are deeply connected to the water that flows across the land, in and out of our homes, and back to our wells, rivers, lakes, aquifers, and marine waters. For some parts of the County, that includes Puget Sound. 

Water is so important to our to quality of life and public health that Water Pollution Control is regulated by the Washington State Legislature.  It's also regulated by the U.S. government. In 1948, the United States enacted the Federal Water Pollution Control Act, which was revamped in 1972 and became known as the “Clean Water Act.” Under this program,  standards were set to limit harmful substances from entering the water we all share. 

Since January of 2007, Thurston County has been required to comply with these federal and state water pollution control laws. The County was issued a municipal stormwater permit (Permit) by the Washington Department of Ecology, which requires the County to take a number of actions to manage where and how rainwater from storms, or “stormwater,” enters our streams, rivers, lakes, and groundwater within the regulated area (PDF).  While rain is a natural occurrence, the byproducts of our society—such as pavement, oil from vehicles, and yard chemicals—are picked up and carried to our vital water sources during storms.


​Obligations for Thurston County

The Permit requires the County to develop, implement, and annually update a Stormwater Management Program Plan (PDF) designed to reduce discharges of pollutants from its municipal stormwater systems to protect water quality. This plan requires the following program components:

  • Operations and maintenance – An operations and maintenance program to prevent or reduce pollutant runoff from County owned and operated facilities and municipal operations.

  • Monitoring & assessment – The County meets its monitoring and assessment obligations by choosing the compliance option that allows paying into a collective fund to implement a Regional Stormwater Monitoring Program. The County also operates monitoring stations to help evaluate local water resource conditions, although that's not an obligation under the Permit.

  • Illicit discharge detection & elimination – An ongoing program to prevent, find, and eliminate illicit connections and illicit discharges into the County’s municipal stormwater system. This also involves mapping the County’s stormwater outfalls and discharge points as well as County owned and operated stormwater treatment, flow control facilities, and conveyances (i.e., pipes and ditches). Report illicit discharge by calling (360) 867-2099 or submitting a report.

  • Controlling runoff from new development, redevelopment, and construction sites – A program to reduce pollutants in stormwater runoff to the County’s stormwater system. This program applies to private and public development, including roads and parking lots. Thurston County’s Drainage Design and Erosion Control Manual (PDF) sets standards for reducing and managing stormwater runoff in the unincorporated areas of Thurston County, including maintenance and inspection of private stormwater facilities to ensure they continue to function properly.


  • Public education and outreach – A program to reduce or eliminate behaviors and practices that cause or contribute to adverse stormwater impacts as well as encourage participation in stewardship activities.

  • Public involvement and participation – Provide opportunities for public input in the development and implementation of the County’s Stormwater Management Program Plan. Ways to get involved include sharing your comments and ideas directly with the Utility’s Program Manager and participating in our volunteer-based activities. The County also utilizes a citizen advisory board to review and make recommendations regarding issues affecting the County’s Stormwater Utility.

In addition to developing and implementing these programs, the Permit requires the County to submit an annual report (PDF) to the Washington State Department of Ecology documenting the County’s progress in fulfilling the Permit’s requirements.